The San Francisco 49ers announced that running back Christian McCaffrey will miss the rest of the regular season due to a PCL injury, joining backup Jordan Mason on injured reserve. This adds to the team's injury woes as they sit in last place in the NFC West with a 5-7 record. McCaffrey's absence, following previous Achilles tendon issues earlier in the season, leaves rookie Isaac Guerendo as the lead back. The 49ers will need to rally for a playoff push amid these setbacks and have faced difficulties maintaining their running game.